Are polarized sunglasses good for everything?

While polarized sunglasses are excellent in most circumstances for vibrant and detailed vision, there are some situations whereby polarized sunglasses may not be suited such as when viewing older screens or displays, when pilots are flying and at nighttime.

Flying. Pilots need to view gauges and instruments that use treated glass. This thereby usually renders polarized sunglass lenses unsuitable for pilots when flying.

Nighttime. Polarized lenses are not suitable for nighttime wear.

Viewing screens or displays. When viewing older model screens or displays through a polarized lens, the screen or display may appear to have black blotches, seem very dark or appear to be blank. This is common in older model devices with liquid crystal screens such as computer screens, smart watches, smart phones or the car digital dashboard.

When the screen appears to have black blotches or appear blank, this phenomenon occurs because the liquid crystals do not emit light themselves, they only reflect horizontal light. Meanwhile, polarized lenses block horizontal light waves only allowing vertical light waves to reach the eye. The result is the appearance of a black, blank or dark screen or display. A work around for this effect – if possible – is to rotate the screen or device by 90 degrees. This will then allow the light of the screen through the polarized lens.